758

#include <iostream>
#include <fstream>

using namespace std;

struct Node {
    Node* l;
    Node* r;
    int val;
    Node(int val) :val(val), l(nullptr), r(nullptr){}
};

Node* root = nullptr;

void add(int a, Node* cur) {
    if (cur == nullptr) {
        root = new Node(a);
        return;
    }
    if (a < cur->val) {
        if (cur->l == nullptr) {
            cur->l = new Node(a);
            return;
        }
        add(a, cur->l);
    }
    else if (a > cur->val) {
        if (cur->r == nullptr) {
            cur->r = new Node(a);
            return;
        }
        add(a, cur->r);
    }
}

int count(Node* cur) {
    if (cur == nullptr) return 0;
    return count(cur->l) + count(cur->r) + 1;
}

int main() {
    ifstream fin("input.txt");
    ofstream fout("output.txt");

    int a;
    fin >> a;
    while (a != 0) {
        add(a, root);
        fin >> a;
    }
    fout << count(root) << endl;

    fin.close();
    fout.close();
    return 0;
}